Seeing as some wireless charging pads look like skateboards already, why not enlist the most famous skateboard of all to be a wireless charger, the hoverboard from Back to the Future. Just lay a phone and top of the board and you’ll have enough power to traverse over water. Maybe.
The hoverboard sits on a clear plastic base to give the illusion that it is hovering in place. The design seen here is about the size of a keyboard, but could be made as small as a smartphone.
It has two Bluetooth speakers underneath. I doubt it will sound good lying flat*, so the board folds to one side to expose the speakers. The phone can be placed on an easel located on the aforementioned clear plastic base.
It would be nice to charge the phone and use the speakers at the same time, so maybe a solution can be found for the potential sound issues. Maybe aim the speakers up and put some holes on the top surface of the board?
Then again, the magnets of the speakers might not play well with the charging technology, so this idea could very well be toast. At the very least, this hoverboard could be one gadget or the other, not both.
*Then again, it might sound okay. My PC speakers sound fine when pointed downwards at my desk surface with a few inches of clearance.